The present invention relates to a cleaning system for cleaning fluid-conducting tubing. The invention is particularly useful in a condenser for cleaning the tubing of the heat-exchanger used in such a condenser, and the invention is therefore described below with respect to this application.
The present invention is particularly directed to an improvement in the cleaning system described in our U.S. Pat. No. 4,865,121. That patent describes a cleaning system for cleaning tubing used for conducting a fluid therethrough, which system includes balls circulated with the fluid through the tubing from its upstream side to its downstream side, means for separating the balls from the fluid at the downstream side of the tubing, and recirculating means for recirculating the balls back to the upstream side of the tubing; characterized in that the recirculating means comprises a chamber, a first passageway from the chamber to the downstream side of the tubing where the balls are separated from the fluid, and a second passageway leading from the chamber to the atmosphere or another point of lower pressure than in the chamber. The second passageway includes a valve effective when opened to produce, by the difference in pressure between the downstream side of the tubing and the atmosphere (or another point of lower pressure), a flow of the fluid and balls from the downstream side of the tubing to the chamber. The cleaning system further includes a separator between the chamber and the second passageway to permit the fluid, but not the balls, to flow through the second passageway to the atmosphere (or another point of lower pressure).
In one embodiment described in that patent, the system further included an ejector effective to positively eject all the balls collected in the mentioned chamber into the upstream side of the tubing; and in the separator was in the form of a screen defining one wall of the mentioned chamber adjacent to the second (outlet) passageway. However, in such an arrangement, the balls tend to accumulate on the inner surface of the separator screen, and therefore when the ejector is actuated to eject the balls collected in the chamber into the upstream side of the tubing, the balls tended to jam between the ejector and the inner surface of the screen. They thus interfere with the operation of the ejector, and also they become damaged during the operation of the ejector.
An object of the present invention is to provide a cleaning system of the foregoing type which eliminates the foregoing disadvantages.